.nav{
    overflow: hidden;
    /* 隐藏不代表删除 */
}
.sk{
    position: absolute;
    top: 40px;
    left: 193px;
}
.sk_list ul li {
    float: left;
}
.sk_list ul li a {
    display: block;
    line-height: 45px;
    padding: 0 29px;
    font-size: 16px;
    font-weight: 700;
    color: #000;

}
.sk_con ul li {
    float: left;
}
.sk_con ul li a {
    display: block;
    line-height: 47px;
    padding: 0 20px;
}
.sk_con ul li:last-child a::after{
    content:'\e91e';
    font-family: 'icomoon';

}
.sk_bd  li {
float: left;
overflow: hidden;
width: 290px;
height: 460px;
border: 1px solid transparent;
margin-right: 13px;
}
.sk_bd  li:hover{
    border: 1px solid red;
}
.sk_bd  li:nth-child(4n){
    margin-right: 0;
}